Major impact of moist wound healing on autologous tissue regeneration: A review of ulcer treatment

Ulcers are frequently intractable and can be venous in origin or arise from injuries, such as finger amputations or burns. Venous ulcers are most common in the lower extremities, affecting approximately 1% of the United States population. Although clinical practice guidelines of the Society for Vascular Surgery recommend moist dressings for wound care, the rate of dressing usage, excluding gauze, in 2016 was <10% in Japan. Compared with conventional treatments such as disinfection and gauze, endovenous ablation of venous reflux; adequate varicose vein resection, including incompetent perforator veins; and compression therapy with moist wound healing and appropriate skin care, yield more rapid epithelialization and prevent a recurrence. This study aimed to describe the widespread use of moist wound healing for venous ulcer treatment in Japan and its application to various wounds, particularly difficult‐to‐treat finger amputations and burns.

adequate varicose vein resection, including incompetent perforator veins 1 ; and compression therapy with moist wound healing 2 and appropriate skin care, yield more rapid epithelialization and prevent a recurrence. This study aimed to describe the widespread use of moist wound healing for venous ulcer treatment in Japan and its application to various wounds, particularly difficult-to-treat finger amputations and burns.

| MATERIALS AND METHODS
The development of irreversible membrane (IRM) dressings (Plus Moist™; Zuiko Medical Osaka) and composite absorbent pads (Zuikopad™; Zuiko Medical Osaka) in Japan have improved the moist wound healing technique. 2 Showering wounds twice daily, regardless of their possible infections, and covering them using these functional dressings could provide an optimal environment for tissue regeneration through excess exudate absorption and wet wound surface maintenance. Natsui reported ˃4000 cases where moist wound healing was used, 3 reflecting its increasing popularity. 4 3 | RESULTS

| Finger amputation
More than 110 finger amputation cases were presented from the ˃4000 reported cases, including minor cases where the apex part of the finger was amputated with a blade, contusions, and fractures and cases where vascular anastomosis or composite grafts were performed at several hospitals. Moist wound healing results in almost complete epithelialization without necessitating reamputation. Figure 1A shows a complete regeneration of finger tears that would have been indicated for amputation using conventional methods. 2,5 Some deformities and shortening of the fingers are unavoidable in major amputation cases; however, no complications were observed in moving the treated finger in most cases. Furthermore, no patient underwent skin grafting or vascular anastomosis in Natsui's study. 3 Cases of conservative treatment of finger amputation using IRM dressings have also been reported. 6

| Burns
Natsui achieved epithelial regeneration without major joint contraction using moist wound healing in patients with burns, presenting many cases from actual clinical practice 3 ( Figure 1B). Moreover, many similar cases have been reported. 7

| DISCUSSION
Although regeneration took approximately 5 months in previous reports, no scarring was observed in completely regenerated fingertips. Finger amputation, managed surgically or conservatively (revision amputation), is more common in the United States. 6 Moist wound healing has reduced the need for skin grafts and even treating third-degree burns, despite requiring a longer treatment period. Traditionally, skin grafts are recommended for unhealed wounds for approximately 2 weeks after a burn injury. However, skin grafting is generally accompanied by the disfigurement of both the harvest and grafting sites. Moist wound healing could prevent joint contracture, even with hypertrophic scarring, by promoting the active movement of the wound, which preserves the joint's range of motion.
In contrast, skin grafting is associated with unfavorable joint contractures and requires wound immobilization. Although epithelialization may take weeks to years, the risk of infection is lower for moist wound healing. 4,8 Generally, larger wounds take longer to heal.

ACKNOWLEDGMENTS
The author would like to thank Editage (www.editage.com) for English language editing.

CONFLICTS OF INTEREST
The authors declare no conflicts of interest.

DATA AVAILABILITY STATEMENT
Data are available upon request to the corresponding author, Kenji Yamamoto, who had full access to all data in this study and takes full responsibility for the integrity of the data and the accuracy of the data analysis.

ETHICS STATEMENT
This study was approved by the Institutional Review Board of Okamura Memorial Hospital (approval number: A019-001), and the need for individual patient consent was waived. Informed consent forms were obtained, as applicable.

TRANSPARENCY STATEMENT
The lead author Kenji Yamamoto affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.